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Software defined networks
Flimel, Peter ; Smékal, Zdeněk (referee) ; Filka, Miloslav (advisor)
This diploma work describes the software-defined network focusing on optical networks. Subsequently designed their own software network that is implemented in the environment OMNeT ++. This work deals with SDN (software-defined network), and impact on current communications environment in the world of telecom-munications services.
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Dispersion measurements of optical transmissions.
Motúz, Rastislav ; Urban, František (referee) ; Filka, Miloslav (advisor)
This thesis firstly theoretically describes phenomena which appear in optical fiber transmission. The theoretical part of the thesis deals with linear and non-linear phenomena, and later on proceeds to dispersions with a more significant effect on the optical transmission quality. It puts polarization to the centre of the phenomenon called Polarization mode dispersion (PMD), which is the main object of our interest. It leads to a deep PMD description from the point of view of polarization states, limit values, compensation methods, and methods of measurement. The practical part of this thesis deals with a draft of PMD measurement via Fixed Analyzer method. For the purposes of this measurement, we used the optical spectral analyzer MS9740A. In order to compare measured values, the proposed idea then proceeds to the reference measurement by using a modular platform EXFO FTB--200 in combination with CD/PMD module EXFO FTB-5700. Results of measurements have been evaluated for the limit values defined by the standard. In the last chapter of this thesis, the reference measurements are compared to the Fixed Analyzer method. All the advantages and disadvantages of individual measurement methods are identified at the end of this chapter too.
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The impact of polarization mode dispersion on error-rate of optical fibre link
Dorociak, Petr ; Křivánek, Vítězslav (referee) ; Kyselák, Martin (advisor)
Master’s thesis engages in the impact of polarization mode dispersion on optical communication system. Polarization mode dispersion is mathematically described by Stoke’s and Jone’s space and ensure the theoretic causes of the rise of polarization mode dispersion that are divided on the external and internal effects. On the basis of these effects grow up a differential group delay (DGD) which makes causes that individual polarization modes have between them a time delay and limitation of maximum bit rate. Then master´s thesis analyses the influence of the polarization mode dispersion on the pulse enlargement and on the modulation signal. In this work, there are described the most applicated optical modulation formats. Polarization mode dispersion has also influence on the bit error rate of optical fibre link and closing of eye diagram too. Eye diagram is used to view the transmission characteristics and diagnoses the channel errors. Eye diagram is connected with the definitions as a bit error rate (BER) and signal-to-noise ratio (SNR) that are explained in this work too. Following the gained experiences it was designed an useful graphic interface to display the effect of the polarization mode dispersion on the transmitted signal. Realization of the graphic interface is created in the program MATLAB. In Matlab-Simulink are created six models according to the kind of modulations with characteristic AWGN (Additive White Gaussian Noise) channel. Program was tested for a typical values. In all calculations it is counted only with the losses that are caused by the polarization mode dispersion. It is not calculated with the losses that are caused by a chromatic dispersion and attenuation. At the end of this work are evaluated all types of modulation formats depending on the polarization mode dispersion, optical fibre length, price and complexity of the realization. Atteined results of my master’s thesis are compared with two foreign articles.
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3D metal printing
Vrána, Pavel ; Herčík, Tomáš (referee) ; Řiháček, Jan (advisor)
The work presents a literature search of current technologies for 3D metal printing. In the introduction, the individual methods are divided according to the forms of material into powder, wire, and string. The methods using metal powder are SLS, EBM, and DED. Other methods are ADAM, PMD, and WAAM. For each technology are described the principle, printable materials, usage, and example of the product. For methods using electric arc are described possible metal transfers and their limitations.
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Optical Proximity Sensor with Time-of-Flight Measuring Principle
Mlatecová, Hana ; Kopečný, Lukáš (referee) ; Žalud, Luděk (advisor)
3D optical proximity scanner is described in this thesis. The sensor is marked as 03D201 and is made by Ifm electronic, GmbH company. The text also describes the basic characteristics, measuring principle, PC connection method and communication. A program for communication between PC and sensor was created and named O3D_Application. This program provides functions for real-time data transfer and visualization. Measured data can be saved easily by this program. The thesis also contains an analysis of measured data and parasitic parameters of the sensor.
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The Optical Fibre Dispersion Effects on Multiplex Transmission Systems
Kyselák, Martin ; Filka, Miloslav (advisor)
This doctoral thesis deals with present trend to turn up the bit rate of the optical fibres making use of wavelenght multiplex systems. There are new theoretical and practical problems caused by the new technologies. Except the known modal dispersion there exist problems caused by chromatical and polarization mode dispersion. In the opening of the thesis the known effects, which influence the payload signal, are introduced. The polarization mode dispersion has the main attention. Within the scope of this thesis there has been programmed the statistical calculator which can analyses the measured values of differential group delay by Monte Carlo calculation. Next meaningful output is the designating application of the optical routes. It is possible to mathematicaly unambiguously define the polarization mode dispersion by Jones, Stokes and Poynting vectors. This complicated calculations are mechanized and in the simulation application make possible to simulate the signification of the PMD influence at different input parameters. The thesis includes the study of the PMD modulation format impact with the results of simulations and confrontation with other scientists results. The significant output are the final practical results examinations, which can be implemented thanks to the possibility of using the FTB-5500B measuring device.
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Connecting the TV studios
Flimel, Peter ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
In this bachelor thesis work is done TV link study in 2020, for the purpose of mediation football matches between studies in Prague and Bratislava. This work deals with optical connections and technology matters to revel in the transmission of large amounts of data.
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Polarization mode dispersion
Turský, Aleš ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
The work deals with dispersive effects of single mode fibers. We learn about the chromatic dispersion, the main attention is paid to the Polarization Mode Dispersion. We clarify the root cause origin of the Polarization Mode Dispersion describing parameters and its effect on transmitted data. Further on, the works dedicates to measure methods of the Polarization Mode Dispersion which is the interferometric method or the POTDR method. We explain the ways of the PMD removal at contemporary optic routes and options of PMD compensation by using compensators of various types. There is also mentioned the possibility of profiting from the soliton transmission. The last chapter deals with measuring of a real optic route. It includes measured data and its evaluation due to the ITU-T demands.
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Reliability, security and transfer parameters of optical cables
Kučera, Zdeněk ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Communication via fiber optic cable is the latest advancement of the transmission media currently used for data transmission. Despite initial problems, using of this medium in recent years has greatly expanded due to their indisputable advantages. Optical cable is a great combination of reliability and security of data transfer. Its constantly improving transmission parameters contribute to the high speeds in the long-distance transmission of data. In the theoretical part of this work some kinds of optical cables are mentioned, also the most important parameters and the most widely used methods of measurement of these cables. The comparison and evaluation of the measured values of attenuation and the real length of optical paths was done by several types of measuring instruments in the practical part.
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Polarization in optical fiber
Bilek, Maroš ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
In the theoretical part of the the bachelor's thesis, the first part is devoted to the analysis of the spread of the light beam in the fiber, the parameters of light and various types of fibers. Subsequently, the phenomenon of polarization, its conditions, methods of depiction and writing are described in detail. Furthermore, the issue of polarization mode dispersion (PMD) is explained. Bindings, differential group delay and PMD measurement methods are described. The practical section of the thesis describes the methods and procedures for measuring polarization and polarization mode dispersion. The EXFO FTB-200 measuring platform was used to measure PMD and was equipped with a module for PMD/CD measurement. A polarimeter in combination with a polarization analyzer was used to measure polarization. As part of the long-term measurements, the EXFO FTB-200 measuring instrument was reused in the case of PMD. In the case of polarization measurements, a combination of polarimeter and balance detector was used. Finally, the results of both short- and long-term measurements are displayed. The results of short-term polarization measurements are shown in the form of both, a Poincaré sphere and a polarizing ellipse with a calculated azimuth and ellipticity. Long-term measurements are in the form of graphs that show changes in polarization rotation rate over time. From the displayed results, the dependency of polarization and therefore PMD on the environmental surroundings is concluded.
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